In a small bowl, combine 200 ml of lukewarm water with a pinch of sugar. Sprinkle the yeast over the water and stir gently. Allow the mixture to sit for about 10 minutes, or until it becomes frothy and bubbly.

In a large mixing bowl, add 500 g of all-purpose flour and 1 teaspoon of salt. Create a well in the center and pour in the activated yeast mixture along with 50 g of softened butter. Mix until a rough dough forms, then knead for about 5-10 minutes.

Shape the kneaded dough into a ball and place it in a lightly greased bowl, covering it with a damp towel. Let it rise for 40-60 minutes, or until it has doubled in size.

Once your dough has risen, gently punch it down. Divide the dough into 12 equal pieces, rolling each into a smooth ball.

Preheat your oven to 200°C (390°F).

In a large pot, bring 1.75 liters of water to a near boil. Slowly add 50 g of baking soda while stirring.

Using a slotted spoon, lower each muffin into the boiling soda bath, boiling for about 30 seconds per side.

Sprinkle the tops of the muffins with coarse salt, then place in the preheated oven. Bake for approximately 20 minutes or until golden brown.